81537489600 has 1008 divisors, whose sum is σ = 328836381696. Its totient is φ = 17611776000.

The previous prime is 81537489587. The next prime is 81537489613. The reversal of 81537489600 is 698473518.

It is an interprime number because it is at equal distance from previous prime (81537489587) and next prime (81537489613).

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 386433495 + ... + 386433705.

Almost surely, 2^81537489600 is an apocalyptic number.

81537489600 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81537489600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (164418190848).

81537489600 is an abundant number, since it is smaller than the sum of its proper divisors (247298892096).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81537489600 is a wasteful number, since it uses less digits than its factorization.

81537489600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 334 (or 312 counting only the distinct ones).

The product of its (nonzero) digits is 1451520, while the sum is 51.

The spelling of 81537489600 in words is "eighty-one billion, five hundred thirty-seven million, four hundred eighty-nine thousand, six hundred".